Sylvester Version

1 files changed, 696 insertions, 0 deletions

diff --git a/g10/armor.c b/g10/armor.c
new file mode 100644
index 000000000..f6e6305d4
--- /dev/null
+++ b/g10/armor.c
@@ -0,0 +1,696 @@
+/* armor.c - Armor filter
+ *	Copyright (c) 1997 by Werner Koch (dd9jn)
+ *
+ * This file is part of G10.
+ *
+ * G10 is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * G10 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "errors.h"
+#include "iobuf.h"
+#include "memory.h"
+#include "util.h"
+#include "filter.h"
+#include "packet.h"
+#include "options.h"
+
+
+
+
+#define CRCINIT 0xB704CE
+#define CRCPOLY 0X864CFB
+#define CRCUPDATE(a,c) do {						    \
+			a = ((a) << 8) ^ crc_table[((a)&0xff >> 16) ^ (c)]; \
+			a &= 0x00ffffff;				    \
+		    } while(0)
+static u32 crc_table[256];
+static byte bintoasc[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+			 "abcdefghijklmnopqrstuvwxyz"
+			 "0123456789+/";
+static byte asctobin[256]; /* runtime initialized */
+static int is_initialized;
+
+typedef enum {
+    fhdrINIT=0,
+    fhdrLF,
+    fhdrWAIT,
+    fhdrWAITINFO,
+    fhdrWAITCLEARSIG,
+    fhdrDASH,
+    fhdrHEAD,
+    fhdrDASH2,
+    fhdrINFO
+} fhdr_state_t;
+
+struct fhdr_struct {
+    fhdr_state_t state;
+    int count;
+    int hdr_line; /* number of the header line */
+    char buf[256];
+};
+
+
+/* if we encounter this armor string with this index, go
+ * into a mode, which fakes packets and wait for the next armor */
+#define BEGIN_SIGNED_MSG_IDX 3
+static char *head_strings[] = {
+    "BEGIN PGP MESSAGE",
+    "BEGIN PGP PUBLIC KEY BLOCK",
+    "BEGIN PGP SIGNATURE",
+    "BEGIN PGP SIGNED MESSAGE",
+    NULL
+};
+static char *tail_strings[] = {
+    "END PGP MESSAGE",
+    "END PGP PUBLIC KEY BLOCK",
+    "END PGP SIGNATURE",
+    NULL
+};
+
+
+static void
+initialize(void)
+{
+    int i, j;
+    u32 t;
+    byte *s;
+
+    /* init the crc lookup table */
+    crc_table[0] = 0;
+    for(i=j=0; j < 128; j++ ) {
+	t = crc_table[j];
+	if( t & 0x00800000 ) {
+	    t <<= 1;
+	    crc_table[i++] = t ^ CRCPOLY;
+	    crc_table[i++] = t;
+	}
+	else {
+	    t <<= 1;
+	    crc_table[i++] = t;
+	    crc_table[i++] = t ^ CRCPOLY;
+	}
+    }
+    /* build the helptable for radix64 to bin conversion */
+    for(i=0; i < 256; i++ )
+	asctobin[i] = 255; /* used to detect invalid characters */
+    for(s=bintoasc,i=0; *s; s++,i++ )
+	asctobin[*s] = i;
+
+    is_initialized=1;
+}
+
+/****************
+ * Check wether this is a armored file or not
+ * See also parse-packet.c for details on this code
+ * Returns: True if it seems to be armored
+ */
+static int
+is_armored( byte *buf, size_t len )
+{
+    int ctb, pkttype;
+
+    if( len < 28 )
+	return 0; /* not even enough space for the "---BEGIN"... */
+
+    ctb = *buf;
+    if( !(ctb & 0x80) )
+	return 1; /* invalid packet: assume it is armored */
+    pkttype =  ctb & 0x40 ? (ctb & 0x3f) : ((ctb>>2)&0xf);
+    /*lenbytes = (ctb & 0x40) || ((ctb&3)==3)? 0 : (1<<(ctb & 3));*/
+    switch( pkttype ) {
+      case PKT_PUBLIC_CERT:
+      case PKT_SECRET_CERT:
+      case PKT_PUBKEY_ENC:
+      case PKT_SIGNATURE:
+      case PKT_COMMENT:
+      case PKT_PLAINTEXT:
+      case PKT_COMPRESSED:
+      case PKT_ENCRYPTED:
+	return 0; /* seems to be a regular packet: not armored */
+    }
+
+    return 1;
+}
+
+
+
+
+static int
+find_header( struct fhdr_struct *fhdr, int c )
+{
+    int i;
+    const char *s;
+
+    if( c == '\n' ) {
+	switch( fhdr->state ) {
+	  case fhdrINFO:
+	    if( !fhdr->count )
+		return 1;   /* blank line: data starts with the next line */
+	    fhdr->buf[fhdr->count] = 0;
+	    log_debug("armor line: '%s'\n", fhdr->buf );
+	    /* fall through */
+	  case fhdrWAITINFO:
+	    fhdr->state = fhdrINFO;
+	    fhdr->count = 0;
+	    break;
+	  case fhdrWAITCLEARSIG:
+	    if( fhdr->count++ == 1 ) /* skip the empty line */
+		return 1; /* clear signed text follows */
+	    else if( fhdr->count > 1 )
+		fhdr->state = fhdrWAIT; /* was not valid */
+	    break;
+	  default:
+	    fhdr->state = fhdrLF;
+	    break;
+	}
+    }
+    else {
+	switch( fhdr->state ) {
+	  case fhdrINIT:
+	  case fhdrLF:
+	    if( c == '-' ) {
+		fhdr->state = fhdrDASH;
+		fhdr->count = 1;
+	    }
+	    else
+		fhdr->state = fhdrWAIT;
+	    break;
+	  case fhdrWAIT:
+	  case fhdrWAITINFO:
+	  case fhdrWAITCLEARSIG:
+	    break;
+	  case fhdrDASH:
+	    if( c == '-' ) {
+		if( ++fhdr->count == 5 ) {
+		    fhdr->state = fhdrHEAD;
+		    fhdr->count = 0;
+		}
+	    }
+	    else
+		fhdr->state = fhdrWAIT;
+	    break;
+	  case fhdrHEAD:
+	    if( c != '-' ) {
+		if( fhdr->count < DIM(fhdr->buf)-1 )
+		    fhdr->buf[fhdr->count++] = c;
+	    }
+	    else {
+		fhdr->buf[fhdr->count] = 0;
+		for(i=0; (s=head_strings[i]); i++ )
+		    if( !strcmp(s,fhdr->buf) )
+			break;
+		if( s ) { /* found string; wait for trailing dashes */
+		    fhdr->hdr_line = i;
+		    fhdr->state = fhdrDASH2;
+		    fhdr->count = 1;
+		}
+		else
+		    fhdr->state = fhdrWAIT;
+	    }
+	    break;
+
+	  case fhdrDASH2:
+	    if( c == '-' ) {
+		if( ++fhdr->count == 5 ) {
+		    fhdr->state = fhdrWAITINFO;
+		    log_debug("armor head: '%s'\n",
+					head_strings[fhdr->hdr_line]);
+		    fhdr->state = fhdr->hdr_line == BEGIN_SIGNED_MSG_IDX
+				   ? fhdrWAITCLEARSIG : fhdrWAITINFO;
+		    if( fhdr->state == fhdrWAITCLEARSIG )
+			fhdr->count = 0;
+		}
+	    }
+	    else
+		fhdr->state = fhdrWAIT;
+	    break;
+
+	  case fhdrINFO:
+	    if( fhdr->count < DIM(fhdr->buf)-1 )
+		fhdr->buf[fhdr->count++] = c;
+	    break;
+
+	  default: abort();
+	}
+    }
+    return 0;
+}
+
+/****************
+ * check wether the trailer is okay.
+ * Returns: 0 := still in trailer
+ *	    -1 := Okay
+ *	    1 := Error in trailer
+ */
+static int
+check_trailer( struct fhdr_struct *fhdr, int c )
+{
+    return -1;
+    /* FIXME: implement this ! */
+}
+
+
+/* figure out wether the data is armored or not */
+static int
+check_input( armor_filter_context_t *afx, IOBUF a )
+{
+    int rc = 0;
+    int c;
+    size_t n = 0, nn=0, nn_limit=0;
+    struct fhdr_struct fhdr;
+
+    assert( DIM(afx->helpbuf) >= 50 );
+    memset( &fhdr, 0, sizeof(fhdr) );
+
+    /* read a couple of bytes */
+    for( n=0; n < DIM(afx->helpbuf); n++ ) {
+	if( (c=iobuf_get(a)) == -1 )
+	    break;
+	afx->helpbuf[n] = c & 0xff;
+    }
+
+    if( !n )
+	rc = -1;
+    else if( is_armored( afx->helpbuf, n ) ) {
+	for(nn=0; nn < n; nn++ )
+	    if( find_header( &fhdr, afx->helpbuf[nn] ) )
+		break;
+	if( nn == n ) { /* continue read */
+	    while( (c=iobuf_get(a)) != -1 )
+		if( find_header( &fhdr, c ) )
+		    break;
+	    if( c == -1 )
+		rc = -1; /* eof */
+	}
+	if( !rc && fhdr.hdr_line == BEGIN_SIGNED_MSG_IDX ) {
+	    /* start fake package mode (for clear signatures) */
+	    nn++;
+	    afx->helplen = n;
+	    afx->helpidx = nn;
+	    afx->templen = 0;
+	    afx->tempidx = 0;
+	    afx->fake = m_alloc_clear( sizeof(struct fhdr_struct) );
+	}
+	else if( !rc ) {
+	    /* next byte to read or helpbuf[nn+1]
+	     * is the first rad64 byte */
+	    nn++;
+	    afx->inp_checked = 1;
+	    afx->crc = CRCINIT;
+	    afx->idx = 0;
+	    afx->radbuf[0] = 0;
+	    afx->helplen = n;
+	    afx->helpidx = nn;
+	}
+    }
+    else {
+	afx->inp_checked = 1;
+	afx->inp_bypass = 1;
+    }
+
+    return rc;
+}
+
+
+
+/* fake a literal data packet and wait for an armor line */
+static int
+fake_packet( armor_filter_context_t *afx, IOBUF a,
+	     size_t *retn, byte *buf, size_t size  )
+{
+    int rc = 0;
+    int c;
+    size_t n = 0, nn=0, nn_limit=0;
+    struct fhdr_struct *fhdr = afx->fake;
+    byte *helpbuf = afx->helpbuf;
+    int helpidx = afx->helpidx;
+    int helplen = afx->helplen;
+    byte *tempbuf = afx->tempbuf;
+    int tempidx = afx->tempidx;
+    int templen = afx->templen;
+    int defer=1;
+
+    /* FIXME: have to read one ahead or do some other mimic to
+     * get rid of the lf before the "begin signed message"
+     */
+    size = 100; /* FIXME: only used for testing (remove it)  */
+    n = 2; /* reserve 2 bytes for the length header */
+    while( n < size-2 ) { /* and 2 for the term header */
+	if( templen && (fhdr->state == fhdrWAIT || fhdr->state == fhdrLF) ) {
+	    if( tempidx < templen ) {
+		buf[n++] = tempbuf[tempidx++];
+		continue;
+	    }
+	    tempidx = templen = 0;
+	}
+
+	if( helpidx < helplen )
+	    c = helpbuf[helpidx++];
+	else if( (c=iobuf_get(a)) == -1 )
+	    break;
+	if( find_header( fhdr, c ) ) {
+	    m_free(afx->fake);
+	    afx->fake = NULL;
+	    afx->inp_checked = 1;
+	    afx->crc = CRCINIT;
+	    afx->idx = 0;
+	    afx->radbuf[0] = 0;
+	    /* we don't need to care about the tempbuf */
+	    break;
+	}
+	if( fhdr->state == fhdrWAIT || fhdr->state == fhdrLF ) {
+	    if( templen ) {
+		tempidx = 0;
+		continue;
+	    }
+	    buf[n++] = c;
+	}
+	else if( fhdr->state == fhdrWAITINFO
+		|| fhdr->state == fhdrINFO )
+	    ;
+	else { /* store it in another temp. buf */
+	    assert( templen < DIM(afx->tempbuf) );
+	    tempbuf[templen++] = c;
+	}
+    }
+    buf[0] = (n-2) >> 8;
+    buf[1] = (n-2);
+    if( !afx->fake ) { /* write last (ending) length header */
+	buf[n++] = 0;
+	buf[n++] = 0;
+    }
+
+    afx->helpidx = helpidx;
+    afx->helplen = helplen;
+    afx->tempidx = tempidx;
+    afx->templen = templen;
+    *retn = n;
+    return rc;
+}
+
+
+
+static int
+radix64_read( armor_filter_context_t *afx, IOBUF a, size_t *retn,
+	      byte *buf, size_t size )
+{
+    byte val;
+    int c, c2;
+    int checkcrc=0;
+    int rc = 0;
+    size_t n = 0, nn=0;
+    int  idx, i;
+    u32 crc;
+
+    crc = afx->crc;
+    idx = afx->idx;
+    val = afx->radbuf[0];
+    for( n=0; n < size; ) {
+	if( afx->helpidx < afx->helplen )
+	    c = afx->helpbuf[afx->helpidx++];
+	else if( (c=iobuf_get(a)) == -1 )
+	    break;
+	if( c == '\n' || c == ' ' || c == '\r' || c == '\t' )
+	    continue;
+	else if( c == '=' ) { /* pad character: stop */
+	    if( idx == 1 )
+		buf[n++] = val;
+	    checkcrc++;
+	    break;
+	}
+	else if( (c = asctobin[(c2=c)]) == 255 ) {
+	    log_error("invalid radix64 character %02x skipped\n", c2);
+	    continue;
+	}
+	switch(idx) {
+	  case 0: val =  c << 2; break;
+	  case 1: val |= (c>>4)&3; buf[n++]=val;val=(c<<4)&0xf0;break;
+	  case 2: val |= (c>>2)&15; buf[n++]=val;val=(c<<6)&0xc0;break;
+	  case 3: val |= c&0x3f; buf[n++] = val; break;
+	}
+	idx = (idx+1) % 4;
+    }
+    for(i=0; i < n; i++ )
+	crc = (crc << 8) ^ crc_table[(crc >> 16)&0xff ^ buf[i]];
+    crc &= 0x00ffffff;
+    afx->crc = crc;
+    afx->idx = idx;
+    afx->radbuf[0] = val;
+    if( checkcrc ) {
+	afx->inp_eof = 1; /*assume eof */
+	for(;;) { /* skip lf and pad characters */
+	    if( afx->helpidx < afx->helplen )
+		c = afx->helpbuf[afx->helpidx++];
+	    else if( (c=iobuf_get(a)) == -1 )
+		break;
+	    if( c == '\n' || c == ' ' || c == '\r'
+		|| c == '\t' || c == '=' )
+		continue;
+	    break;
+	}
+	if( c == -1 )
+	    log_error("premature eof (no CRC)\n");
+	else {
+	    u32 mycrc = 0;
+	    idx = 0;
+	    do {
+		if( (c = asctobin[c]) == 255 )
+		    break;
+		switch(idx) {
+		  case 0: val =  c << 2; break;
+		  case 1: val |= (c>>4)&3; mycrc |= val << 16;val=(c<<4)&0xf0;break;
+		  case 2: val |= (c>>2)&15; mycrc |= val << 8;val=(c<<6)&0xc0;break;
+		  case 3: val |= c&0x3f; mycrc |= val; break;
+		}
+		if( afx->helpidx < afx->helplen )
+		    c = afx->helpbuf[afx->helpidx++];
+		else if( (c=iobuf_get(a)) == -1 )
+		    break;
+	    } while( ++idx < 4 );
+	    if( c == -1 )
+		log_error("premature eof (in CRC)\n");
+	    else if( idx != 4 )
+		log_error("malformed CRC\n");
+	    else if( mycrc != afx->crc )
+		log_error("CRC error; %06lx - %06lx\n",
+				    (ulong)afx->crc, (ulong)mycrc);
+	    else {
+		struct fhdr_struct fhdr;
+
+		memset( &fhdr, 0, sizeof(fhdr) );
+		for(rc=0;!rc;) {
+		    rc = check_trailer( &fhdr, c );
+		    if( !rc ) {
+			if( afx->helpidx < afx->helplen )
+			    c = afx->helpbuf[afx->helpidx++];
+			else if( (c=iobuf_get(a)) == -1 )
+			    rc = 2;
+		    }
+		}
+		if( rc == -1 )
+		    rc = 0;
+		else if( rc == 2 )
+		    log_error("premature eof (in Trailer)\n");
+		else
+		    log_error("error in trailer line\n");
+	    }
+	}
+    }
+
+    if( !n )
+	rc = -1;
+
+    *retn = n;
+    return rc;
+}
+
+
+/****************
+ * The filter is used to handle the armor stuff
+ */
+int
+armor_filter( void *opaque, int control,
+	     IOBUF a, byte *buf, size_t *ret_len)
+{
+    size_t size = *ret_len;
+    armor_filter_context_t *afx = opaque;
+    int rc=0, i, c, c2;
+    byte radbuf[3];
+    int  idx, idx2;
+    size_t n=0;
+    u32 crc;
+
+    if( DBG_FILTER )
+	log_debug("armor-filter: control: %d\n", control );
+    if( control == IOBUFCTRL_UNDERFLOW && afx->inp_bypass ) {
+	for( n=0; n < size; n++ ) {
+	    if( (c=iobuf_get(a)) == -1 )
+		break;
+	    buf[n] = c & 0xff;
+	}
+	if( !n )
+	    rc = -1;
+	*ret_len = n;
+    }
+    else if( control == IOBUFCTRL_UNDERFLOW ) {
+	if( size < 20 )
+	    log_bug(NULL); /* supplied buffer maybe too short */
+
+	if( afx->inp_eof ) {
+	    *ret_len = 0;
+	    if( DBG_FILTER )
+		log_debug("armor-filter: eof due to inp_eof flag\n" );
+	    return -1;
+	}
+
+	if( afx->fake )
+	    rc = fake_packet( afx, a, &n, buf, size );
+	else if( !afx->inp_checked ) {
+	    rc = check_input( afx, a );
+	    if( afx->inp_bypass )
+		;
+	    else if( afx->fake ) {
+		/* the buffer is at least 20 bytes long, so it
+		 * is easy to construct a packet */
+		buf[0] = 0xaf; /* old packet format, type 11, var length */
+		buf[1] = 0;    /* set the length header */
+		buf[2] = 6;
+		buf[3] = 't';  /* canonical text */
+		buf[4] = 0;    /* namelength */
+		buf[5] = buf[6] = buf[7] = buf[8] = 0; /* timestamp */
+		n = 9;
+	    }
+	    else if( !rc )
+		rc = radix64_read( afx, a, &n, buf, size );
+	}
+	else
+	    rc = radix64_read( afx, a, &n, buf, size );
+
+	*ret_len = n;
+    }
+    else if( control == IOBUFCTRL_FLUSH ) {
+	if( !afx->status ) { /* write the header line */
+	    if( afx->what >= DIM(head_strings) )
+		log_bug("afx->what=%d", afx->what);
+	    iobuf_writestr(a, "-----");
+	    iobuf_writestr(a, head_strings[afx->what] );
+	    iobuf_writestr(a, "-----\n");
+	    iobuf_writestr(a, "Version: G10 pre-release "  VERSION "\n");
+	    iobuf_writestr(a, "Comment: This is a alpha test version!\n\n");
+	    afx->status++;
+	    afx->idx = 0;
+	    afx->idx2 = 0;
+	    afx->crc = CRCINIT;
+	}
+	crc = afx->crc;
+	idx = afx->idx;
+	idx2 = afx->idx2;
+	for(i=0; i < idx; i++ )
+	    radbuf[i] = afx->radbuf[i];
+
+	for(i=0; i < size; i++ )
+	    crc = (crc << 8) ^ crc_table[(crc >> 16)&0xff ^ buf[i]];
+	crc &= 0x00ffffff;
+
+	for( ; size; buf++, size-- ) {
+	    radbuf[idx++] = *buf;
+	    if( idx > 2 ) {
+		idx = 0;
+		c = bintoasc[(*radbuf >> 2) & 077];
+		iobuf_put(a, c);
+		c = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077];
+		iobuf_put(a, c);
+		c = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
+		iobuf_put(a, c);
+		c = bintoasc[radbuf[2]&077];
+		iobuf_put(a, c);
+		if( ++idx2 > (72/4) ) {
+		    iobuf_put(a, '\n');
+		    idx2=0;
+		}
+	    }
+	}
+	for(i=0; i < idx; i++ )
+	    afx->radbuf[i] = radbuf[i];
+	afx->idx = idx;
+	afx->idx2 = idx2;
+	afx->crc  = crc;
+    }
+    else if( control == IOBUFCTRL_INIT ) {
+	if( !is_initialized )
+	    initialize();
+    }
+    else if( control == IOBUFCTRL_FREE ) {
+	if( afx->status ) { /* pad, write cecksum, and bottom line */
+	    crc = afx->crc;
+	    idx = afx->idx;
+	    idx2 = afx->idx2;
+	    for(i=0; i < idx; i++ )
+		radbuf[i] = afx->radbuf[i];
+	    if( idx ) {
+		c = bintoasc[(*radbuf>>2)&077];
+		iobuf_put(a, c);
+		if( idx == 1 ) {
+		    c = bintoasc[((*radbuf << 4) & 060) & 077];
+		    iobuf_put(a, c);
+		    iobuf_put(a, '=');
+		    iobuf_put(a, '=');
+		}
+		else { /* 2 */
+		    c = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077];
+		    iobuf_put(a, c);
+		    c = bintoasc[((radbuf[1] << 2) & 074) & 077];
+		    iobuf_put(a, c);
+		    iobuf_put(a, '=');
+		}
+		++idx2;
+	    }
+	    /* may need a linefeed */
+	    if( idx2 < (72/4) )
+		iobuf_put(a, '\n');
+	    /* write the CRC */
+	    iobuf_put(a, '=');
+	    radbuf[0] = crc >>16;
+	    radbuf[1] = crc >> 8;
+	    radbuf[2] = crc;
+	    c = bintoasc[(*radbuf >> 2) & 077];
+	    iobuf_put(a, c);
+	    c = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077];
+	    iobuf_put(a, c);
+	    c = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
+	    iobuf_put(a, c);
+	    c = bintoasc[radbuf[2]&077];
+	    iobuf_put(a, c);
+	    iobuf_put(a, '\n');
+	    /* and the the trailer */
+	    if( afx->what >= DIM(tail_strings) )
+		log_bug("afx->what=%d", afx->what);
+	    iobuf_writestr(a, "-----");
+	    iobuf_writestr(a, tail_strings[afx->what] );
+	    iobuf_writestr(a, "-----\n");
+	}
+    }
+    else if( control == IOBUFCTRL_DESC )
+	*(char**)buf = "armor_filter";
+    return rc;
+}
+